Effect of prophylactic dressings to reduce pressure injuries: a polymer‑based skin model

Objective: This study evaluated the effect of pressure injury (PI) prophylactic dressings used for patients at high risk of PI development to reduce friction, shear force and pressure, and their combined force, in an original polymer-based skin model. Method: A low-friction outer-layer hydrocolloid (LFH) dressing and a multilayered silicone foam (MSF) dressing were used. Before application, compression and friction properties were measured. Our original experimental model—the ‘simulated skin-shearing test’—consisted of: a weight; a polyurethane-based skin model containing a three-axis tactile sensor; dressings; a table covered with bedsheets; and a mechanical tester, by which the interface friction force, internal shear force and pressure were measured continuously during skin model movements. An estimated combined force generated by internal shear and pressure was represented as a vector. A model with no dressing was used as a control. Results: The LFH dressing had significantly higher compression strength versus the MSF dressing. In contrast, the dynamic coefficient of friction was lower for the LFH dressing versus the MSF dressing (p<0.05). In simulated skin-shearing test results, shear forces were 0.45N and 0.42N for LFH and MSF dressings, respectively, with no significant difference. The estimated combined force was lower for the MSF dressing compared with that of the LFH dressing and control. Conclusion: The shear force-reducing effect in the skin model was equivalent between the LFH and MSF dressings. However, the MSF dressing significantly reduced the force generated by a combination of internal shear force and pressure compared with the LFH dressing.